The Telex RTS CES-2 is a complete earset kit for intercom systems. It includes an RTV-04 Earset Receiver, a CMT-98 5' Headphone Cable with a 3.5mm connector, and an ET-4 Acoustic Eartube.
The RTV-04 from Telex is a small and lightweight earset receiver in the Telethin line of products. It has an impedance of 125 ohms.
The CMT-98 is a 5' (1.5m) cable for Telex intercom headphones and headsets. It terminates with a 1/8" (3.5mm) straight connector.
The Telex ET-4 is an acoustic eartube with a coiled cable in a clear plastic finish, designed for discreet on-camera IFB use or personal and assisted listening, and a component of the Telex patented Telethin receiver-based earsets. The ET-4 is supplied with a set of small, medium and large earcones.